Coating process and composition for same

ABSTRACT

There is disclosed a composition for forming a protective coating upon a substrate. The composition has been found particularly useful for forming a protective coating upon components of automotive vehicles, such as a bedliner for a pick-up truck. The composition may include, without limitation, an isocyanate component and an amine component and optionally includes one or more of a catalyst, stabilizer, pigment, fire retardant or other additives.

CROSS-REFERENCE TO A RELATED PATENT APPLICATION

The present application is a continuation of U.S. application Ser. No.10/036,122, filed Dec. 26, 2001 now U.S. Pat. No. 6,613,389, thecontents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a composition useful for forming aprotective coating on a substrate and to a process for using the same.

BACKGROUND OF THE INVENTION

Historically, coatings have been applied to substrates, both to protectthe substrates and to improve the properties of the substrates. Forexample, and without limitation, coatings have been developed to protectsubstrates from various environmental conditions and to protectsubstrates during contact of the substrates with other objects.Moreover, coatings have been developed to improve properties ofsubstrates such as durability, strength, environmental resistance andthe like.

In the automotive industry, coatings are used for protecting variouscomponents of an automotive vehicle. As an example, coatings are usedfor protecting vehicle components against cosmetic damage (e.g.,degradation, marring, denting) due to corrosion, abrasions, impacts,chemicals, ultraviolet light, thermal cycling or the like. While, it isdesirable for such coatings to protect against cosmetic damage, it isalso desirable to provide a composition that is relatively easy tohandle, and particularly exhibits relatively low volatile emissions.Thus, the present invention provides a composition for forming a coatingwith improved protection capabilities, ease of handling and relativelylow volatile emissions.

SUMMARY OF THE INVENTION

The present invention meets the above needs and others by providing acomposition and process for coating a substrate. The process includescontacting the substrate with a composition including an isocyanate inan amount up to about 75% by volume of the composition, the isocyanatebeing at least 75% aliphatic by weight; and an amine in an amount up toabout 75% by volume of the composition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. illustrates a process and apparatus for applying the compositionto form a protective coating on a substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a process and composition for forming aprotective coating upon a substrate. In a preferred embodiment, thecomposition forms a protective coating on a substrate provided by one ormore components of an automotive vehicle. In a highly preferredembodiment, the composition forms a protective coating on a surface of apick-up truck bed, and thus forms a bed-liner for such pick-up truck.

The composition preferably includes at least two components:

-   -   1) an isocyanate component; and    -   2) an amine component.

The isocyanate component in the composition may include a singleisocyanate or a mixture of two or more different isocyanates. Amounts ofisocyanate present in the composition may range up to about 75% byvolume, and more preferably range from about 30% to about 70% by volume.Even more preferably, the isocyanate is present in the composition fromabout 40% to about 60% by volume and most preferably from about 45% toabout 55% by volume.

Preferred isocyanates of the present composition may be monoisocyanates,diisocyanates, polyisocyanates or a combination thereof. Included in thedefinition of isocyanates are the isocyanates themselves, or optionallydimers, trimers, prepolymers or quasi-prepolymers thereof withactive-hydrogen components (e.g., obtainable from use of a polyol,amine-terminated polyether, or otherwise).

Exemplary monoisocyanates include, without limitation, isophoronemonoisocyanate, 3,5-dimethylphenyl isocyanate, paratoluenesulfonylmonoisocyanate.

Representative examples of diisocyanates include, without limitation,4,4′-diisocyanatodiphenylmethane, p-phenylene diisocyanate,1,3-bis(isocyanatomethyl)-cyclohexane, 1,4-diisocyanatocyclohexane,1,5-naphthalene diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate,4,4′-diisocyanatodicyclohexylmethane, and 2,4-toluene diisocyanate, ormixtures thereof. More preferred examples include4,4′-diisocyanato-dicyclohexylmethane and4,4′-diisocyanatodiphenylmethane, 4,4′-diisocyanatodiphenylmethane.Other potential isocyanates include, without limitation, triisocyanatessuch as toluene-2,4,6-triisocyanate and isocyanates such as4,4′-dimethyidiphenylmethane-2,2′,5′5′-tetraisocyanate and the diversepolymethylene polyphenyl polyisocyanates.

Isocyanates of the present invention may be aromatic or aliphatic (e.g.,cycloaliphatic). It is preferred, however, that the major portion of theisocyanate composition is aliphatic. In one preferred embodiment, atleast 75% of the isocyanate is aliphatic by weight, more preferably atleast 90% of the isocyanate is aliphatic by weight and even morepreferably at least 99% of the isocyanate is aliphatic by weight.

In one embodiment, preferably, the isocyanate has an NCO equivalentweight of at least about 130, more preferably at least about 160, andmost preferably at least about 200; and is preferably no greater thanabout 500, more preferably no greater than about 400, and mostpreferably no greater than about 300. Moreover, it is desirable for theisocyanate to have a relatively low residual monomer level that ispreferably less than about 1% by weight, more preferably less than about0.2% by weight and most preferably less than about 0.05% by weight. Suchlow residual monomer level can assist in lowering volatile emissionlevels while handling the unreacted component or during application ofthe composition.

In a highly preferred embodiment, the isocyanate includes a liquidaliphatic isocyanate oligomer or prepolymer based upondicyclohexylmethane 4,4′-diisocyanate (H₁₂MDI), isophorone diisocyanate(IPDI), tetramethyl-1,3-xylylene diisocyanate (TMXDI), hexamethylenediisocyanate (HDI) or a mixture thereof.

One highly preferred isocyanate is a dimerized, trimerized or thebiureted form of hexamethylene diisocyanate (HDI) or itsquasi-prepolymer. An example of such a composition is DESMODUR XP-7100,which is commercially available from Bayer Corporation, Pittsburgh, Pa.

The amine is present in the composition for reacting with the isocyanatecomponent of the composition, and preferably forming a urea linkage. By“amine component” herein, it is meant a component having an aminefunctional group, such as molecules, compounds, oligomers, polymers, orthe like having an amine termination or active hydrogens that are aminehydrogens. The amount of amine may be any suitable amount for achievingthe desired amount of urea. For instance, the amine may be present inthe composition in an amount up to about 75% by volume and morepreferably from about 30% to about 70% by volume. Even more preferably,the amine is present in the composition from about 40% to about 60% byvolume and even more preferably from about 45% to about 55% by volume.

Amines suitable for the composition of the present invention may beprimary, secondary, tertiary amines or mixtures thereof. The amines mayby monoamines, diamines, triamines or mixtures thereof. The amines maybe aromatic or aliphatic (e.g., cycloaliphatic), but are preferablyaliphatic. The amine preferably is provided as a liquid having arelatively low viscosity (e.g., less than about 100 mPa·s at 25° C.).Particularly preferred resins of the composition are primarily basedupon secondary amines or mixtures of primary and secondary amines. Forexample, if a mixture of primary and secondary amines is employed,preferably the primary amine is present in an amount up to about 50parts by volume, with the secondary amine present in an amount up toabout 100 parts by volume. Though others can be used, primary aminespresent is the resin preferably have a molecular weight greater thanabout 200 (e.g., for reduced volatility), and secondary amines presentin the resin are preferably diamines with molecular weights of at leastabout 190 (e.g., about 210-230).

In one preferred embodiment, the amine is a resin that includes at leastone secondary amine at the amount of 20% to 100%, preferably 40% to 80%,and more preferably about 50% to 70% by volume. Suitable secondaryamines include mono-functional acrylate or methacrylate modifiedaliphatic polyamines. Examples of the aliphatic polyamines includes,without limitation, ethylamine, the isomeric propylamines, butylamines,pentylamines, hexylamines, cyclohexylamine, ethylene diamine,1,2-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane,1,6-diaminohexane, 2-methyl-1,5-pentane diamine,2,5-diamino-2,5-dimethylhexane, 2,2,4- and/or2,4,4-trimethyl-1,6-diamino-hexane, 1,11-diaminoundecane,1,12-diaminododecane, 1,3- and/or 1,4-cyclohexane diamine,1-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane, 2,4- and/or2,6-hexahydrotoluylene diamine, 2,4′- and/or 4,4′-diamino-dicyclohexylmethane and 3,3′-dialkyl-4,4′-diamino-dicyclohexyl methanes (such as3,3′-dimethyl-4,4′-diamino-dicyclohexyl methane and3,3′-diethyl-4,4′-diamino-dicyclohexyl methane), 2,4- and/or2,6-diaminotoluene and 2,4′- and/or 4,4′-diaminodiphenyl methane, ormixtures thereof.

An example of a particularly preferred amine includes an aliphaticamine, such as a cycloaliphatic polyamine with high steric hindrancethat is optionally modified with an n-butyl group. One such amine isavailable commercially from UOP under the designation of CLEARLINK™.Another example of a particularly preferred amine is an acrylic modifiedprimary amine.

In another highly preferred embodiment, the amine is provided as anamine-functional resin. More preferably, such amine-functional resin isa relatively low viscosity, amine-functional resin suitable for use inthe formulation of high solids polyurethane/polyurea coatings. Onehighly preferred amine-functional resin is substantially free ofsolvent. Though any of a number of different resins may be suitable, apreferred resin is an ester of an organic acid. For example, one highlypreferred amine is an aspartic ester-based amine-functional reactiveresin that is compatible with isocyanates (e.g., one that is solventfree, and/or has a mole ratio of amine functionality to the ester of nomore than 1:1 so there remains no excess primary amine upon reaction),such as DESMOPHEN NH 1220 commercially available from Bayer Corporation,Pittsburgh, Pa. Of course, other suitable compounds containing aspartategroups may be employed as well. Other examples of particularly preferredsecondary polyamines are polyaspartic esters, which are derivatives ofcompounds such as maleic acid, fumaric acid esters, aliphatic polyaminesand the like.

Such compounds may be prepared in any suitable art-disclosed manner. Byway of example, without limitation, the subject matter described in U.S.Pat. Nos. 5,126,170, 5,236,741 or both, hereby incorporated byreference, may be employed as guidance. For instance primary monoaminesor polyamines may be reacted with substituted or unsubstituted maleic orfumaric acid esters.

Without limitation, examples of substituted or unsubstituted maleic orfumaric acid esters suitable for preparing the aspartic esters includedimethyl, diethyl and di-n-butyl esters of maleic acid and fumaric acid,mixtures of maleates and fumarates, and the corresponding maleic acidesters, fumaric acid esters, or mixtures thereof, substituted by methylin the 2-position, 3-position or both.

Examples of suitable amines for preparing the aspartic esters includewithout limitation ethylamine, the isomeric propylamines, butylamines,pentylamines, hexylamines, cyclohexylamine, ethylene diamine,1,2-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane,1,6-diaminohexane, 2-methyl-1,5-pentane diamine,2,5-diamino-2,5-dimethylhexane, 2,2,4- and/or2,4,4-trimethyl-1,6-diamino-hexane, 1,11-diaminoundecane,1,12-diaminododecane, 1,3- and/or 1,4-cyclohexane diamine,1-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane, 2,4- and/or2,6-hexahydrotoluylene diamine, 2,4′- and/or 4,4′-diamino-dicyclohexylmethane and 3,3′-dialkyl-4,4′-diamino-dicyclohexyl methanes (such as3,3′-dimethyl-4,4′-diamino-dicyclohexyl methane and3,3′-diethyl-4,4′-diamino-dicyclohexyl methane), 2,4- and/or2,6-diaminotoluene and 2,4′- and/or 4,4′-diaminodiphenyl methane, ormixtures thereof.

One example of the polyaspartic esters is the derivative of diethylmaleate and 1,5-diamino-2-methylpentane, available commercially fromBayer Coporation, Pittsburgh, Pa. under the trade name Desmophen NH1220.

Another group of preferred polyaspartic esters are derivatives ofdialkyl maleate or furmarate and cycloaliphatic polyamines with thechemical structure of R—(CH₂—NH₂)_(n), where, n>2, and R represents anorganic group which is inert towards isocyanate groups at a temperatureof 100° C. or less, and contains at least one cycloaliphatic ring. Anexample, without limitation, is 1,3- or 1,4-bis-aminomethyl cyclohexane,or the mixture thereof.

The amine resin component may also include high molecular weight primaryamines, such as polyoxyalkyleneamines at the amount of 0 to 50%,preferably 10% to 40%, and more preferably 20% to 30%. Thepolyoxyalkyleneamines contain two or more primary amino groups attachedto a backbone, such as propylene oxide, ethylene oxide, or a mixturethereof. Examples of such amines include those offered under thedesignation JEFFAMINE™ from Huntsman Corporation, preferably with amolecular weight ranging from about 200 to about 7500, such as, withoutlimitation, JEFFAMINES D-230, D-400, D-2000, T-403 and T-5000.

Other suitable ingredients, such as isocyanates, amines or aminefunctional resins suitable for use in the present invention includethose disclosed in U.S. Pat. Nos. 5,236,741; 5,243,012; 6,013,755; and6,180,745, all of which are hereby incorporated by reference for allpurposes.

It should be recognized that concentrates or diluted forms of thepresent composition may be employed, pursuant to which the proportion ofthe amine to isocyanate assumes a proportion corresponding with theabove volume percentages. Thus, for example, in one embodiment, theamine and the isocyanate are present in an amount of about 1:10 to about10:1 parts by volume, and more preferably about 1:3 to about 3:1 partsby volume, and still more preferably about 1:1 parts by volume. Forexample, a highly preferred proportion is about 1.3:1 parts by volume ofamine to isocyanate.

In addition to amine and isocyanate, the composition may include one ormore additional ingredients for functioning as a catalyst, stabilizer,pigment, fire retardant or other performance or property modifier.Preferably, and as described below, any such additives are provided aspart of the amine-based resin prior to combination of the resin with theisocyanate. However, it is contemplated that various ingredients of thecomposition may be combined with the isocyanate prior to combining theremaining ingredients.

In a highly preferred embodiment, the present composition employs nocatalyst. However, in certain embodiments, it is possible that one ormore art-disclosed catalysts may be provided in the composition asdesired. Examples include conventional polyurethane catalysts, such asorganometallic catalysts (e.g., stannous compounds).

One or more stabilizers may be provided in the composition. Preferably,the resin includes an ultraviolet (UV) light absorber and a visiblelight absorber for assisting coatings formed by the composition inresisting degradation caused by exposure to sunlight. Light absorber ispreferably present in the resin from about 0% to about 10% by weightmore preferably from about 1% to about 7% by weight and even morepreferably from about 2% to about 4% by weight.

Exemplary light stabilizers include, without limitation, hinderedphenols, aromatic amines, organophosphites, thioesters and the like. Ina highly preferred embodiment, the resin includes about 2% by weight ofa hindered amine light stabilizer such as TINUVIN 292 commerciallyavailable from Ciba Specialty Chemicals and about 1% by weight of ahindered amine UV stabilizer such as TINUVIN 1130 also commerciallyavailable from Ciba Specialty Chemicals.

The composition also may preferably include a thermal stabilizer forassisting the coatings formed by the composition in resistingdegradation caused by exposure to thermal cycling. Thermal stabilizer ispreferably present in the resin from about 0% to about 10% by weightmore preferably from about 0.33% to about 2% by weight and even morepreferably from about 0.66% to about 1.33% by weight.

Exemplary light stabilizers include, without limitation, hinderedphenols, aromatic amines, organophosphites, thioesters and the like.Preferably, the thermal stabilizer in the composition is an antioxidant.One highly preferred antioxidant is a phenolic antioxidant such asoctadecyl 3,5-di-(tert)-butyl4-hydroxyhydrocinnamate sold under thetradename IRGANOX 1076 and commercially available form Ciba SpecialtyChemicals.

One or more fire retardants may also be provided in the composition.Fire retardat is preferably present in the resin from about 0% to about10% by weight more preferably from about 1% to about 7% by weight andmore preferably from about 2% to about 4% by weight.

Exemplary fire retardants include, without limitation, powdered or fumedsilica, layered silicates, aluminum hydroxide, brominated fireretardants, tris(2-chloroethyl)phosphate, tris(2-chloropropyl)phosphate,tris(2,3-dibromopropyl)phosphate, tris(1,3-dichloropropyl)phosphate,diammonium phosphate, various halogenated aromatic compounds, antimonyoxide, alumina trihydrate, polyvinyl chloride, and the like, andcombinations thereof.

Furthermore, one or more pigments may be provided in the composition.Pigment is preferably present in the resin from about 0% to about 20% byweight more preferably from about 3% to about 15% by weight and morepreferably from about 6% to about 8% by weight. In a highly preferredembodiment, the resin includes a titanium dioxide pigment such as TRONOX600I commercially available from the Kerr-McGee Corporation.

The resin may also include components for controlling static such asabout 2% to 5% by weight of a conductive carbon black, KETJENBLACKEC-300J commercially available from Ketjenblack InternationalCorporation, a joint venture of Ferro-Plast and Akzo Nobel Chemicals. Ahighly preferred static controlling agent is a metal salt, such as apotassium salt (e.g. potassium hexafluorophosphate), which may beprovided in an amount up to about 0.4% by weight of the resin. In ahighly preferred embodiment, a potassium salt is dissolved in apropylene glycol with amine functionality and thereafter mixed in theresin.

To prevent sagging of the uncured coating of composition on, forexample, a vertical surface, the composition may also include athixotropic agent (thickener) in an amount of about 0 to 10%, preferablyabout 1% to 8%, and more preferably about 2% to 4%. The thixotropicagent may also help in preventing the phase separation of pigments andother solids from the liquid chemicals during storage, transportationand application. Examples of thixotropic agents include, withoutlimitation, fumed silica, such as CAB-O-SIL TS-720 and CAB-O-SIL PTGcommercially available from Cabot Corp., bentonite clay or the like. Theagent may be liquid or solid, or a combination thereof.

The composition may also include other additives such as fillers or evenfibrous reinforcement (e.g., for forming a composite).

The various ingredients of composition may be combined and applied to asubstrate according to a variety of combination and applicationprotocols to form protective coatings. Preferably, the isocyanate isseparated from the amine until a short period of time (e.g., preferablyless than about 5 minutes, more preferably less than about 60 secondsand most preferably less than about 10 seconds) prior to application ofthe composition to a substrate. The composition may be applied to asurface of a substrate using suitable art-disclosed techniques,including but not limited to brushing, rolling, dipping, dripping,extruding, curtain coating, swabbing, spraying or the like. Moreover,the composition may be applied continuously or intermittently upon asurface of a substrate.

Nearly any substrate may receive the composition to form a coatingthereon. The composition may be applied to metal, plastic, or compositesubstrates, wood substrates or the like. In preferred embodiments, thecomposition is applied to coated or uncoated surfaces of metalcomponents. In highly preferred embodiments, the composition is appliedto painted or e-coated surfaces of automotive components (e.g., to forma truck bedliner, by coating one or more of the floor, side walls, headboard, tail gate or other component of a pick-up truck cargo box) andmay be applied in addition to or as a replacement for a clear coat.Depending on the desired texture of the coating, the composition may beapplied to achieve a smooth surface (e.g., a class A finish) or aroughened or even coarse surface over part or all of the surface.

In certain embodiments, the coated or uncoated surface of a substratemay be treated prior to application of the composition. The surface of asubstrate, may be sanded, scuffed, primed or otherwise treated prior toapplication of the composition to the substrate. For example, it may bedesirable to apply a suitable adhesion promoter or primer to the surfaceto be coated. An example of one such primer is available commerciallyfrom The Dow Chemical Company under the name BETAGUARD™ 67725.Advantageously, such pre-treatment techniques can assist the coatingformed on the substrate to tenaciously adhere to the surface of thesubstrate. In a highly preferred embodiment, the substrate ispre-treated with a plasma, for example, for ionizing oxygen (O₂)molecules that are then directed toward the surface of the substrate. Inthis manner, the plasma treatment forms suitable groups (e.g., ketone orhydroxyl groups) that bond with the composition such that thecomposition forms a coating that is even more tenaciously adhered to thesurface of the substrate. Of course, other suitable surface treatmentsmay be employed as desired. Examples of various potential surfacetreatments are described in U.S. Pat. No. 5,298,587; U.S. Pat. No.5,320,875; U.S. Pat. No. 5,433,786; U.S. Pat. No. 5,494,712 U.S. Pat.No. 5,837,958 incorporated herein by reference.

Thus, it will be appreciated that the application of the coatingcomposition of the present invention will result, in certain preferredembodiments, in forming a laminate of a substrate (e.g., metal (such assteel, magnesium, titanium or aluminum), plastic (such as including apolyurethane, a polystyrene, a polyester, polyolefin, a nylon, an epoxy,an acrylic, or the like), a ceramic, a composite, or otherwise),optionally having a layer from a primer or plasma treatment, optionallyhaving one or more coats (e.g., base coat, top coat, clear coat, such asan art-disclosed 2-component urethane or acrylic coating) thereon, andhaving the coating composition of the present invention thereon.

According to one preferred protocol, and referring to FIG. 1, there isillustrated a system 10 for combining isocyanate and amine components toform the composition and for applying the composition to a substrate. Asshown, the system 10 includes a supply 12 of isocyanate and a supply 14of amine-based resin. The system 10 also includes a metering system 20having a first metering container 22 for receiving a predeterminedamount of isocyanate and a second metering container 24 for receiving apredetermined amount of resin. Each of the metering containers 22, 24are in fluid communication with a nozzle 30.

In a preferred approach to applying the composition to a surface, thesurface is prepared as desired and provided at a suitable applicationpoint. The isocyanate and amine-functional components are delivered to asuitable dispenser. Preferably, the components are independently meteredto a mixing chamber, where they are mixed by direct impingement at acontrolled ratio, and thereafter released from the dispenser as a mistor fine spray. For example, with reference to FIG. 1, isocyanate andamine components are pumped from their respective supplies 12, 14 totheir respective metering containers 22, 24. Thereafter, the isocyanateand amine components in the containers 22, 24 are expelled underpressure from the containers 22, 24 to the nozzle 30 (e.g., which may bepart of a gun block) and are expelled from the nozzle 30 as a spray 34.Preferably, the nozzle 30 includes an internal space or cavity (notshown) wherein the isocyanate component and amine component canintermix, atomize or both such that the resulting spray 34 is asubstantially homogeneous composition. The pressure used to expel thespray 34 is preferably greater than about 1000 psi and more preferablybetween about 1500 psi and 2000 psi.

To apply the composition to a substrate, the substrate may be movedrelative to the nozzle 30, the nozzle 30 may be moved relative to thesubstrate or a combination thereof such that the spray 34 is directed atthe substrate for layering the composition on the substrate.

It is contemplated that the application system 10 of FIG. 1 may bedesigned as a robotic system. For example, the nozzle 30, the meteringcontainers 22, 24 or both may be mounted on a robot arm (not show),which may be programmed to move the nozzle 30 as it sprays thecomposition such that a substrate may be coated as desired. Moreover,such a robotic system could apply coatings upon truck bedliners in anautomotive assembly plant or at another location during assembly orformation of a truck. In alternative embodiments, however, thecomposition may be applied after full assembly of a truck.Advantageously, the composition emits minimal airborne chemicals duringapplication such that spraying systems for applying the composition maybe used in a variety of locations.

Although, the composition may be applied at room temperature (e.g.,around 20° C.), it may be desirable to heat the isocyanate, the amine orboth to no greater than about 90° C. prior to application to improve themixing efficiency, flow and wetting properties of the composition duringapplication. Once applied, the composition may be allowed to cure uponthe substrate to form a protective coating. Curing may occur at a widevariety of temperatures. Generally, curing desirably occurs at roomtemperature in the absence of applied heat. However, cooling or heatingmeasures may also be taken to lower or raise the temperature of curing.

In preferred embodiments, the rate of curing of the composition may beat least partially chemically controlled. For example, curing of thecomposition may be controlled by the rate of reaction of the aminecomponent with the isocyanate component. Typically, primary amines reactcomparatively quickly with the isocyanate while secondary amines reactcomparatively slowly. Thus, the amine component may be provided as amixture of primary and secondary amines that are combined according toweight ratios that are chosen as desired to control the rates of curingof the composition to form the coating. Weight ratios of primary amineto secondary amine appropriate for process of application similar to theone described and shown in FIG. 1 are approximately range from about 0:1to about 0.8:1 and is preferably about 0.5:1.

Preferably, the composition is well mixed into a substantiallyhomogeneous liquid mixture prior to application to a substrate. Thus,upon curing (which may be accomplished substantially without the need toapply heat to the coating), the composition will form a substantiallyhomogeneous coating. The coating may be applied in one or more layers ofone or more continuous or variable thickness. Preferred thickness forcoatings on automotive components (e.g., for forming a truck bedliner)range from about 0.5 millimeter to about 20 millimeters, more preferablyfrom about 1 millimeter to about 10 millimeters and most preferably fromabout 3 millimeters to about 5 millimeters. The thickness may varyacross a substrate, randomly or according to a predetermined pattern.

In certain embodiments, the protective coatings formed according to thepresent invention exhibit various advantageous properties. For example,and without limitation, coatings according to the present invention canexhibit strength both adhesive and cohesive up to and greater than 300psi when applied to painted and e-coated surfaces. Additionally,preferred embodiments of the coating exhibit superior resistance todegradation caused by UV radiation, moisture, thermal cycles, chemical(e.g., alkali) exposure, salt and the like. For example, the coatingexhibits substantially no blistering, cracking or charring when sagpanel aged for two weeks at about 70° C. Likewise, upon two weeks ofwater immersion at 32° C., the coating exhibits substantially noblistering, dulling, or softening or loss of adhesion. Like results arealso realizable upon exposure to 100% relative humidity at 38° C. fortwo weeks.

Also advantageously, the coating resists fluid spotting such as fromliquid soap, windshield solvent, coolant, motor oil, bug and tar removeror the like. It resists color change, dulling, softening or surfacedistortion from contact with fuel, as well as from contact with acid oralkali substances.

Table 1 illustrates some additional approximate properties realizablefrom the coating of the present invention.

TABLE 1 Taber Abrasion (wt loss, depth) CS10F: 0.19%, 0.002″ H18: 3.45%,0.017″ Weatherometer Color Retention (ΔL, ΔE)  500 h: −1.64, 1.80 1000h: −1.75, 1.46 Shore A Hardness: 70–90 (more preferably 75–85) Tensile(psi): 1200–2500 (more preferably 1500–2100) Elongation (%): 50–300(more preferably 100–160) Tear (pli): 200–450 (more preferably 250–350)Vol. Resistivity: Antistatic Static: Passes standard Flammability:Self-extinguishes Crocking, dry: AATCC rating 5 Crocking, dry: AATCCrating 5

Moreover, the coating may desirably exhibit anti-skid properties. Eachof the properties discussed make coatings of the present inventiondesirable for protecting automotive vehicle components and especially asa truck bed liner. In a highly preferred embodiment, the coatingcomposition is employed as original equipment for an automotive vehicle,though it may also be provided for after-market application.

Thus, preferably the vehicle is provided and during the vehicle assemblyprocess or otherwise prior to delivery to an end consumer, the vehicleis contacted with the coating composition of the present invention. Theapplication of the coating may be done prior to the vehicle paintingoperation, during the painting operation, or after the paintingoperation. Preferably, application of the coating is performed at thesame facility as the painting of the vehicle. However, it is alsopossible that it is performed at a remote site. The coating may beapplied directly to an untreated or bare surface, to a primed surface,to a surface of a galvannealed steel, to painted surface (e.g., with orwithout a clear coat, or possibly even to a surface coated by oversprayin the painting or other finishing operations of the vehicle).

Of course, the coating composition may also be employed in otherapplications by contacting it with a surface of a substrate, such asthat found in or on a storage container, shipping container, rail car,waste container, pallet, or the like. It may also be suitably employedfor hard surfaces such as panels, doors, flooring, pavement or the like.

The following examples describe, without limitation, one illustrativecomposition in accordance with the present invention.

EXAMPLE 1

Table 2 below provides one precise formulation by weight for anexemplary composition in accordance with the present invention. Thecomposition is formed by combining approximately 56.5% by volume of afirst component (mixed at ambient temperature), with approximately 43.5%by volume of a second component.

TABLE 2 Component I Component II Ingredients (Part by wt.) (Parts bywt.) Oligomer of hexamethylene 100 diisocyanate in solventAmine-functional aspartic acid ester 86 (Desmophen NH 1220) Conductivecarbon black pigment 3 (Ketjenbalck EC-300J) Titanium dioxide filler(Tronox 6001) 7 Antioxidant (Irganox 1076) 1 Ultraviolet Absorber(Tinuvin 1130) 2 Light Absorber (Tinuvin 292) 1

The components of the composition are sprayed onto a surface of apainted bed of a pick up truck, while maintaining the temperature of theingredients at or below about 80° C. The coating is allowed to cure inplace. The resulting coating exhibits adhesive failure at a stress ofgreater than 100 psi (as would be measured by stress applied by anInstron tester to a 6.5 cm² button adhered to the coated surface with a2 part-epoxy resin).

EXAMPLE 2

Example 1 is repeated except that the coating is applied directly to anunpainted e-coated primed surface of the bed. The resulting coatingexhibits cohesive failure at a stress of 400 psi (as would be measuredby stress applied by an Instron tester to a 6.5 cm² button adhered tothe coated surface with a 2 part-epoxy resin).

It should be understood that the invention is not limited to the exactembodiment or construction, which has been illustrated and described butthat various changes may be made without departing from the spirit andscope of the invention.

1. A process for coating a surface of an automotive vehicle, comprising:a) providing a surface of an automotive vehicle, the surface being partof a bedliner of the automotive vehicle; b) contacting the surface toform a coating with a composition comprising: i) a first component thatincludes an isocyanate component including an aliphatic isocyanate as amajor portion of the isocyanate component; and ii) a second componentthat is maintained separate from the first component until mixed in adispenser for application to the surface, the second component includingan amine comprised of an amount of at least one aliphatic primary amineand an amount of at least one secondary amine wherein the secondcomponent includes at least 40% of an aspartic acid ester by weight;wherein upon two weeks of water immersion at 32° C., or exposure to 100%relative humidity at 38° C., the coating exhibits substantially noblistering, dulling or softening or loss of adhesion, and wherein thecoating exhibits substantially no blistering, cracking or charring whensag panel tested for two weeks at about 70° C.; and wherein the amountof the at least one secondary amine is between about 40% and about 80%by volume of the second component and the at least one primary amine isbetween about 10% and about 40% of the second component; and wherein thecoating has a thickness of 1 mm to 10 mm.
 2. A process as in claim 1wherein the isocyanate component is present in the composition fromabout 30% to about 70% by volume and is at least 90% aliphatic by weightand wherein the step of contacting the surface with the compositionincludes spraying the composition upon the surface and wherein thesurface is part of a bedliner of an automotive vehicle.
 3. A process asin claim 2 wherein the composition is contacted with the surface usingan apparatus having a first metering container for receiving the secondcomponent, a second metering container for receiving the first componentand a nozzle in fluid communication with the first and second containersfor spraying the resulting composition.
 4. A process as in claim 2further comprising adding into the composition an effective amount of anagent for controlling static.
 5. A process as in claim 2 wherein the atleast one primary amine present has a molecular weight greater thanabout 200 and the at least one secondary has a molecular weight of atleast about
 190. 6. A process as in claim 5 wherein the isocyanatecomponent has a residual monomer level that is less than about 1% byweight.
 7. A process as in claim 6 wherein the composition includes anagent for controlling static that is a metal salt.
 8. A process as inclaim 1 further comprising adding into the composition a lightstabilizer for assisting the coating in resisting degradation due toexposure to light.
 9. A process as in claim 1 further comprising addinginto the composition a thixotropic agent.
 10. A process as in claim 1wherein at least a portion of the isocyanate component is selected fromthe group consisting of dicyclohexylmethane 4,4′-diisocyanate,isophorone diisocyanate, tetramethyl-1,3-xylylene diisocyanate, andhexamethylene diisocyanate.
 11. A process as in claim 1 wherein thecomposition includes conductive carbon black.
 12. A process as in claim1 wherein the second amine is an ester-based amine functional reactiveresin having a mole ratio of amine functionality to ester of no morethan 1:1.
 13. A process as in claim 1 wherein the composition includespotassium salt as a static controlling agent.
 14. A process as in claim1 wherein the composition includes a thixotropic filler that includesfumed silica.
 15. A process for coating a surface of an automotivevehicle bed liner, comprising: a) providing a surface of an automotivevehicle bed liner; b) robotically spraying the surface with acomposition consisting essentially of: i) a first component thatincludes an isocyanate including an aliphatic isocyanate as a majorportion of the isocyanate component; ii) a second component that ismaintained separate from the first component until mixed in a dispenserfor application to the surface, the second component including an aminein an amount so that the amine and the isocyanate are present in anamount of about 1:10 to about 10:1 parts by volume, the amine beingcomprised of an amount of at least one aliphatic primary amine and anamount of at least one secondary amine; and iii) a static controllingagent that includes a potassium salt; wherein the amount of the at leastone secondary amine is between about 40% and about 80% by volume of thesecond component and the at least one primary amine is between about 10%and about 40% of the second component; and wherein the isocyanate has aresidual monomer level that is less than about 1% by weight; and whereinthe coating has a thickness of 1 mm to 10 mm.
 16. A process as in claim15 wherein the resulting coating exhibits substantially no blistering,cracking or charring when sag panel tested for two weeks at about 70° C.17. A process as in claim 15 wherein upon two weeks of water immersionat 32° C., or exposure to 100% relative humidity at 380° C., the coatingexhibits substantially no blistering, dulling or softening or loss ofadhesion, and wherein the coating exhibits substantially no blistering,cracking or charring when sag panel tested for two weeks at about 70° C.18. A process as in claim 15 wherein the second component includes atleast 40% of an aspartic acid ester by weight.
 19. A process as in claim18 wherein at least a portion of the isocyanate component is selectedfrom the group consisting of dicyclohexylmethane 4,4′-diisocyanate,isophorone diisocyanate, tetramethyl-1,3-xylylene diisocyanate,hexamethylene diisocyanate.
 20. A process as in claim 19, wherein thecomposition further includes a polyoxyalkylenamine.
 21. A process as inclaim 15 wherein the composition includes conductive carbon black.
 22. Aprocess as in claim 15 wherein the at least one primary amine presenthas a molecular weight greater than about 200 and the at least onesecondary has a molecular weight of at least about
 190. 23. A process asin claim 15 wherein: i) the amount of the at least one secondary amineis between about 40% and about 80% by volume of the second component andthe at least one primary amine is between about 10% and about 40% of thesecond component; ii) the isocyanate has a residual monomer level thatis less than about 1% by weight; and iii) the second component includesat least 40% of an aspartic acid ester by weight.
 24. A process as inclaim 15 wherein: i) the second amine is an ester-based amine functionalreactive resin having a mole ratio of amine functionality to ester of nomore than 1:1; and ii) the composition includes a thixotropic fillerthat includes fumed silica.
 25. A process for coating a surface of anautomotive vehicle bed liner, comprising: a) providing a surface of anautomotive vehicle bed liner; b) robotically spraying the surface with acomposition comprising: i) a first component that includes an isocyanatecomponent including an aliphatic isocyanate as a major portion of theisocyanate component; and ii) a second component that is maintainedseparate from the first component until mixed in a dispenser forapplication to the surface, the second component including a secondaryamine that is a aspartic acid ester in an amount so that the amine andthe isocyanate are present in an amount of about 1:10 to about 10:1parts by volume, the amine being comprised of an amount of at least onealiphatic primary amine and an amount of at least one secondary amine;wherein upon two weeks of water immersion at 32° C., or exposure to 100%relative humidity at 38° C., the coating exhibits substantially noblistering, dulling or softening or loss of adhesion, and wherein thecoating exhibits substantially no blistering, cracking or charring whensag panel tested for two weeks at about 70° C.; and wherein thecomposition forms a polyurea coating; and wherein the coating has athickness of 1 mm to 10 mm.
 26. A process as in claim 25 wherein atleast a portion of the isocyanate component is selected from the groupconsisting of dicyclohexylmethane 4,4′-diisocyanate, isophoronediisocyanate, tetramethyl-1,3-xylylene diisocyanate, hexamethylenediisocyanate.
 27. A process as in claim 25 further comprising addinginto the composition an effective amount of an agent for controllingstatic.
 28. A process as in claim 25 wherein the automotive vehicle is apick-up truck, the composition further includes an agent for controllingstatic, and the composition is contacted with the surface using anapparatus having a first metering container for receiving the secondcomponent, a second metering container for receiving the first componentand a nozzle in fluid communication with the first and second containersfor spraying the resulting composition.
 29. A process as in claim 25wherein the composition further includes a polyoxyalkylenamine, and oneor more additional ingredients for functioning as a catalyst,stabilizer, pigment, fire retardant or other performance or propertymodifier.
 30. A process as in claim 25 wherein the at least one primaryamine is present in an amount up to about 50 parts by volume of thesecond component.
 31. A process as in claim 25 wherein the at least oneprimary amine present has a molecular weight greater than about 200 andthe at least one secondary has a molecular weight of at least about 190.32. A process as in claim 25 wherein the amount of the at least onesecondary amine is between about 40% and about 80% by volume of thesecond component and the at least one primary amine is between about 10%and about 40% of the second component.